Extracting tool



June 1o, 1541. H. CAMINEZ 2,244,824

EXTRACTING 'rooiJ Filed Jan. 24. 1939 INVENTOR A492020 CQM//Vfz TTORNEYPatented June 10, 1941 Exrasc'rmc roos Harold Caminos, Kew Gardens, N.Y., assignor to Aircraft Screw Products Company, Inc., Long Island City,N. Y., a corporation of New York Application January 24, 1939, SerialNo. 252,557

2 Claims.

The present invention relates to a tool for extracting a wire coilembedded in the Ithread groove of a female screw member as described inmy copending applications Ser. Nos. 91,263, 190,-

168, and 246,814, filed July 18, 1936, Feb. 12, 1938,

and Dec. 20, 1938, respectively. In the removing of such coils fromtheir seats in threadgrooves diillculties are encountered, because thecoil tends to expand and thus to wedge in the thread groove so much sothat any torque to remove the coil is counteracted by friction.

The object of the present invention is the provision of a tool forfacilitating the removal of such coil, and the invention mainly consistsin a tapered instrument adapted to grip the flrst convolution from theinterior of the coil, and to apply thereto a torque in such. a sense asto screw the coil out of the thread groove. In this manner, the secondand the following. convolution will contract and readily follow themovement oi the tool.

Further details and objects of the invention will be apparent from thedescription hereinafter and the appended drawing illustrating anembodiment thereof by way of example.

In the drawing, Fig. 1 is a side elevation of the tool; Fig. 2, asectional view along line 2-2 of Fig. l, and Fig. 3, a sectionalview ofa female threaded member with a wire coil therein and the new extractingtool applied for removal oi' the coil.

Referring now to the drawing the tool consists of a head portion I, ashank portion' 2 -and a tapered end portion l. The top portion is pro-'vided with a means, e. g. handle I, for applying a torque about thelongitudinal axis I. The end portion 3 is tapered and has at least lonesharp edge intended to engage with the ilrst convolution of a coil. Inthe preferred embodiment the portion 3 has a four cornered cross-sectionas shown in Fig. 2. Two-corners 8 are hook-like projecting from thesubstantially rectangular cross-sectional area and are sharpened so asto grip the coil securely when the tool is used. .For the removal of awire coil 1 embedded in the thread groove 8 of a female member 9v asshown in Fig. 3, the tool is pushed with its end portion l into the coilso that the corners 6 bite into the ilrst convolution I0 of the coil. By'turning the tool in such a sense as to screw the coil out of the threadgroove 8, al1 convolutions will be contracted owing to the frictionbetween the coil and the female member 9, except the first convolutionwhichis spread by the tool proper. Thereby the frictionris sumcientlyreduced for an easy removal of the coil.

I have found that the illustrated form of the tool giv'es the bestresults in removing wire coils of the type described in virtue of thefollowing prevailing conditions: In general, the wire is made of a hardmaterial, but because of its shape is fairly resilient. It is,therefore, necessary that the extracting tool be so designed that it canimbed itself into the hard wire without causing much radial pressurebetween the hard wire and the thread groove in which it is fed. If muchradial pressure is exerted, and particularly if such pressure is exertedsimultaneously at many points of the periphery of one convolution. thehard wire and especially its end, will catch into the softer threadedgroove thereby damaging the tapped hole. One pair of diametricallyopposed edges, therefore, produces the best results. On

the other hand, a tool having only two edges t' vtorque which is appliedthrough the edges l will bear not only against the latter but alsoagainst" the edges I'. In this manner, the extracted portion of the coilwill be suiliciently supported to transmit the extracting force to theconvolutions which are still embedded in the thread groove. 'Ihe bluntedges offer the additional advantage that they guide the tool so as toengage the coil with its two cutting edges at approximatelydiametrically opposite points.

What I claim: l

1. 'An extracting tool for the removal of a wire coil embedded in thethread groove of a female screw member comprising a shank portion and atapered endportion, and means for applying a Atorque about thelongitudinal axis of the tool,

said tapered end portion including two projecting cutting edgesdiametrically opposite each other, and two non-cutting portionsintermediate said cutting edges, said non-cutting portions beingarranged on a smaller diameter than the cutting edges but at such adistance from the shank axis that coil convolutions contracted by saidtool ap- 2 emesse plied thereto may bear against said non-cuttingportions.

2. An extracting tool for the removal of e, wire coil embedded in thethread groove of a, female screw member comprising a shank portion ande. tapered end portion, and means for applying e torque about thelongitudinal axis of the tool,

said tapered end portion having a substantially square cross-section.the ends of the opposite sides of the square, at one pair ofdiametrically opposed corners, projecting slightly beyond the outline ofa true square, and the adjacent ends of the other pair of sides beingcurved so as to form hollow cutting edges with said projecting endsrespectively.

HAROLD CAMINEZ.

